Shift button polarity

A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
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Addicted
Posts: 188
Joined: Mon Oct 14, 2013 7:14 am
Location: Winchester, England

Shift button polarity

Post by Addicted »

Good Morning Gents,

I'm pretty close to finishing my instalation now (Audi 4 speed transmission), just setting up a 'base' tune and have a couple of questions (please say if you would prefer two seperate topics)

Question 1:

Under "standard inputs/outputs configuration" there is the option of "shift button polarity"

however, this option appears contradicted by the setting under "shift input patterns" of "shift button mode" where the only choice is "grounding switches"

In my application both my upshift and downshift buttons are going high. Do I need to alter my circuit so they are grounding (going low) and ignore the "shift button polarity" option?

Or will it work with "shift button polarity" set to going high and "shift button mode" set to "grounding switches"?

Question 2:

Under "solenoid PWM setup"

I only have PWM on the PC output, TCC and Output 3 are on/off, however, the PWM settings for those are not greyed out as I expected. What do I put in those boxes?
Or does the code ignore those variables if TCC and Output 3 are set to on/off?

Thanks guys..
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Shift button polarity

Post by Bernard Fife »

Or will it work with "shift button polarity" set to going high and "shift button mode" set to "grounding switches"?
Addicted,

Yes, it should. The "grounding switches" is a term that goes back to when there was only switches that grounded and a variable voltage for shifting. We will fix the docs, though technically you still have grounding switches (its just that instead of being active when grounded they are inactive when grounded and active otherwise).
What do I put in those boxes?
Ignore them. If you have selected on/off the PWM parameters are ignored in the code. They should be greyed out, and we will fix this too (it is quite complicated, because each of these outputs has many other potential uses as spare ports).

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
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